Exhaust valve mechanisms are commonly used to direct exhaust gases to a truck dump body when the dump body is in the down position or to a muffler means when the dump body is in the up position. In an example, it is common to use a valve having an external linkage arrangement connected to a member moveable by the truck dump body. An overcenter spring is used to move a valve element to block one of the outlets. One problem associated with such an arrangement is that the linkage arrangement can be costly to produce.
The present invention is directed to overcoming one or more of the problems as set forth above.